This invention relates to a linear-moving type displacement detector.
A variety of linear-moving type displacement detectors are known in the art, by means of which a minute mechanical displacement is detected as an electrical signal. In one of these conventional linear-moving type displacement detectors, one movable electrode is disposed between one pair of stationary electrodes to form one pair of variable capacitors, and the two variable capacitors are combined with two oscillators. A mixer is utilized to provide the difference frequency between the output frequencies of the oscillators (cf. German Pat. No. 2,640,057, British Patent Application No. 37302/76, and Swiss Patent Application No. 11367/76).